Measurement Computing StrainBook/616 - Manual (Page 73)

Half-Bridge Configurations
The half-bridge has two strain-variable elements and requires two internal bridge completion resistors (BCRs).
Any bridge resistance from 60 to 1000 ohms can be accommodated for either the internal or external bridge.
Half-Bridge (+), Any Resistance from 60 to 1000 Ohms,
B,D, or F Shunt
IA
External
Bridge DB-9
Input
Internal Bridge Completion
RA RB RC RD RE RF RG
RH
1
2
3
-Sense
+Sense
+Excitation
-Excitation
JN01
Switches
accessed
through
software
1
8
9
7
5
4
3
6
2
H
G
F
E
D
C
B
A
Shunt
BCR
BCR
Shunt
Shunt
Shunt
In this connection, excitation voltage is
regulated at the connector.
This configuration should only be used
for short cable lengths.
Output polarity can be altered by
selecting the software invert function.
The B, D, or F shunt resistor may be
software selected. Output polarity during
shunt calibration will be automatically
corrected by software.
IA
External
Bridge DB-9
Input
Internal Bridge Completion
RA RB RC RD RE RF RG
RH
1
2
3
-Sense
+Sense
+Excitation
-Excitation
JN01
Switches
accessed
through
software
Half-Bridge (+), with Remote Sense
1
8
9
7
5
4
3
6
2 In this connection, excitation voltage is
regulated at the strain gage.
This is the preferred connection for
longer cables.
3-Wire TC Half-Bridge, Software Invert & B, D, F Shunt Available
IA
External
Bridge DB-9
Input
Internal Bridge Completion
RA RB RC RD RE RF RG
RH
1
2
3
-Sense
+Sense
+Excitation
-Excitation
JN01
Switches
accessed
through
software
1
8
9
7
5
4
3
6
2 This occasionally utilized connection can
be made as shown. Two resistors
normally reserved for quarter-bridge
completion must be used.
For compatibility with other
configurations, use of one of the above
two configurations is preferred over
this one.
StrainBook/616 User’s Manual 929494 Bridge Configurations 6-9